There has been provided a tandem color printer having four photosensitive drums that can be integrally detached from a main casing and that correspond to each of four colors yellow, magenta, cyan, and black.
This type of color printer is provided with a drawer frame that can be pulled out of the main casing. The drawer frame supports the four photosensitive drums juxtaposed in a direction parallel to a pull-out direction of the drawer frame. The drawer frame is formed with four cartridge attachment sections corresponding to the photosensitive drums. A developing frame having a developing roller is attached to each cartridge attachment section. When the developing frame runs out of toner, then the developing frame is detached from the drawer frame and replaced with a new one.
Laser printer manufactures and the like are recently urged to meet demand for cost reductions and environmental concerns. In terms of cost reductions and environmental concerns, it is undesirable to replace the entire developing frame that has the developing roller when toner runs out, but it is desirable to replace only a toner cartridge for accommodating toner without replacing the developing frame.
Thus, there has been proposed a toner cartridge that is detachable from the developing frame such that only the toner cartridge can be replaced. The toner cartridge is formed with an opening for supplying toner from the toner cartridge into the developing frame. The toner cartridge is also provided with a shutter for selectively opening and closing the opening so as to prevent toner leakage from the toner cartridge detached from the developing frame.